1938: Fiddling around in the lab one day, Roy Plunkett accidentally discovers polytetrafluoroethylene, soon to be known as Teflon, a slippery substance that will have practical applications in everything from nonstick cookware to a presidential nickname.

Plunkett, a chemist at DuPont's Jackson research lab in New Jersey, made his discovery in the time-honored scientific way: as the result of a mistake, and with an assistant's help.

Plunkett and his assistant, Jack Rebok, were testing the chemical reactions of tetrafluoroethylene, a gas used in refrigeration. The gas was contained in some pressurized canisters, one of which failed to discharge properly when its valve was opened.

Rebok picked up the canister, only to find that it was heavier than an empty canister would be. He suggested cutting it open to see what had happened and, despite the risk of blowing the lab to kingdom come, Plunkett agreed.

Of course, it was heavy: The gas hadn't accidentally escaped. It had solidified into a smooth, slippery white powder as the result of its molecules bonding, a process known as polymerization.

This new polymer was different from similar solids like graphite: It was lubricated better and extremely heat-resistant, due to the presence of dense fluorine atoms that shielded the compound's string of carbon atoms.

Setting other work aside, Plunkett began testing the possibilities of polytetrafluoroethylene, eventually figuring out how to reproduce the polymerization process that had occurred accidentally the first time.

DuPont patented the polymer in 1941, registering it under the trade name Teflon in 1944. The first products — most having military and industrial applications — came to market after World War II. It wouldn't be until the early 1960s that Teflon became a household word when it was used to produce the most effective, heat-resistant cookware yet seen.

The word gained a certain pop-culture notoriety in the 1980s when the media began referring to Ronald Reagan as the Teflon president, a reference to his infuriating ability to avoid being tarnished by the various scandals plaguing his administration.